Teacher education programmes are embedded in both higher and K-12 education contexts. This study explores how collective teacher agency is developed and manifested within two online teacher education courses in a Canadian university and a Chinese university, respectively, under the Covid-19 pandemic context. Employing a digital ethnographic approach, this study reveals that: (1) the structural changes caused by the pandemic create common goals for collective teacher agency to develop; (2) collective teacher agency is motivated by caring for student well-being and honing of teaching skills; and (3) the asynchronous course structure hindered Chinese student teachers' collective efforts to improve teaching but afforded the Canadian group greater collective agency in connecting with their schools. Importantly, this study highlights the role of emotions in facilitating collective agency and argues that emotions are an integral but often overlooked part of teacher agency.